package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

/**
 * @author 梦龙
 * @date 2024/1/5 16:30
 */
@Component
public class RedisIdWorker {

    // 开始时间戳
    private static final long BEGIN_TIMESTAMP =1640995200;

    // 序列号的位数
    private static final int COUNT_BITS = 32;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    // keyPrefix 是业务的前缀，用于区分不同业务
    public long nextId(String keyPrefix) {

        // 1.生成时间戳 31位 s
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowSecond - BEGIN_TIMESTAMP;

        // 2.生成序列号 32位
        // 2.1 获取 当天日期，精确到天
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        Long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);
        // 3.拼接并返回
        return timestamp << COUNT_BITS | count;
    }

    public static void main(String[] args) {
        LocalDateTime time = LocalDateTime.of(2022,1,1,0,0,0);
        long second = time.toEpochSecond(ZoneOffset.UTC);
        System.out.println("second = " + second);
    }


}
